1. Field of the Invention
This invention relates to an optical waveguide substrate and a method of fabricating thereof
2. Related Background Art
Optical waveguide substrates have long been used for branching or coupling of light propagating in optical fibers and other optical transmission media. For example, embedded-type optical waveguide substrates comprise a core for propagation of light, on a Si or other substrate, and cladding covering the core, which is a polymer or other optical waveguide layer. In such an optical waveguide substrate, a wavelength filter or other optical component may be provided so as to intersect the core length direction. In general, optical components are fixed in a state of insertion into a groove, formed for example at a predetermined position in the optical waveguide substrate.
For example, in the following Patent Documents 1 to 6, optical waveguide substrates comprising structures such as those described above are disclosed. In numerous optical waveguide substrates of the prior art, a groove is formed by dicing in an optical waveguide layer on a substrate, and by inserting an optical component into this groove, the optical component is fixed in the optical waveguide layer and substrate. Further, in the following Patent Document 7, a method is disclosed in which, upon insertion of an optical component (optical filter) into a dicing groove, press-fitting material is inserted into the dicing groove together with the optical component to correct bowing of the optical component. As configuration examples other than those above, in the following Patent Document 8, an optical coupler/branch is disclosed in which an optical component (filter) is enclosed between two optical waveguide substrates and fixed in place.
Patent Document 1: Japanese Patent Application Laid-open No. 11-38240
Patent Document 2: Japanese Patent Application Laid-open No. 11-52150
Patent Document 3: Japanese Patent Application Laid-open No. 11-287916
Patent Document 4: Japanese Patent Application Laid-open No. 2000-131527
Patent Document 5: Japanese Patent Application Laid-open No. 2000-75155
Patent Document 6: Japanese Patent Application Laid-open No. 2002-243960
Patent Document 7: Japanese Patent Application Laid-open No. 2002-303772
Patent Document 8: Japanese Patent Application Laid-open No. 2005-77933